Tomato Timer - TomatoTimer is a flexible and easy to use online Pomodoro Technique Timer
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Tasklog App - Tasklog App is an agile productivity software designed to meet the needs of current world freelancers.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
YAPA - Pomodoro timer
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.